How to get product rating and review in magento

/**
* Getting reviews collection object
*/
$productId = $product->getId();
$reviews = Mage::getModel('review/review')
->getResourceCollection()
->addStoreFilter(Mage::app()->getStore()->getId()) 
->addEntityFilter('product', $productId)
->addStatusFilter(Mage_Review_Model_Review::STATUS_APPROVED)
->setDateOrder()
->addRateVotes();
/**
* Getting average of ratings/reviews
*/
$avg = 0;
$ratings = array();
if (count($reviews) > 0) {
foreach ($reviews->getItems() as $review) {
foreach( $review->getRatingVotes() as $vote ) {
$ratings[] = $vote->getPercent();
}
}
$avg = array_sum($ratings)/count($ratings);
}